Roman Numeral Converter
Roman numeral converter that works both ways: turn a number like 2024 into MMXXIV, or a Roman numeral back into a number.
Formula
Standard additive/subtractive Roman notation for 1 to 3999.
Use it from the API
curl "https://moltcalc.com/api/calc/roman-numerals?value=2024"
See the API docs for every endpoint and the input schema.
FAQ
How do Roman numerals work?+
Seven letters carry values: I = 1, V = 5, X = 10, L = 50, C = 100, D = 500 and M = 1000. Values are added left to right, except when a smaller symbol sits before a larger one, where it is subtracted, as in IV = 4 or CM = 900.
What is 2024 in Roman numerals?+
MMXXIV: two thousands (MM), two tens (XX), and four written as IV.
Why does the converter stop at 3999?+
Standard Roman notation has no single symbol above M (1000) and repeats a symbol at most three times, so 3999 (MMMCMXCIX) is the largest number it can express. Larger values historically used an overline to multiply by 1000.